1. Field of the Invention
The present invention relates to a connector to be mounted on a circuit board.
2. Description of the Prior Art
A prior art connector for a circuit board is shown in FIG. 4, and is identified generally by the numeral 1. The prior art connector 1 includes narrow terminals 3 that are bent downwardly after projecting from a rear surface of a connector housing 2. The narrow terminals 3 have their respective leading ends arranged so as to conform to corresponding connection holes H of a circuit board P. When the prior art connector 1 is mounted on the circuit board P, the connector housing 2 is fixed to a specified position of the circuit board P. More particularly, the leading ends of the respective terminals 3 are fitted into the connection holes H and are secured by solder M.
An alignment plate 4 is secured to the connector housing 2 for securely fitting the leading ends of the terminals 3 into the connection holes H. The alignment plate 4 is formed with positioning holes 5 which are in alignment with the connection holes H of the circuit board P. The leading ends of the terminals 3 are passed through the respective positioning holes 5, and thereby are aligned with the corresponding connection holes H.
The connector housing 2, the alignment plate 4 and the circuit board P may undergo a thermal expansion after the connector 1 has been mounted on the circuit board P. This thermal expansion may cause the positioning holes 5 and the connection holes H to be displaced with respect to each other in a direction normal to the extension of the terminals 3 due to a difference in the coefficient of thermal expansion of the individual materials. However, accurate positioning of the terminals 3 requires the positioning holes 5 of the prior art alignment plate 4 to have a smallest size possible. Thus the terminals 3 are fitted into the positioning holes 5 so as not to move therein in directions normal to the extension of the pins. Accordingly, if a force acts to displace the positioning holes 5 of the alignment plate 4 with respect to the connection holes H of the circuit board P, this force is transmitted to the soldered portions M via the terminals 3, thereby increasing stresses in the soldered portions M.
The present invention was developed in view of the above problem, and its object is to improve the alignment of the plurality of terminals, in particular to prevent a stress in a soldered portion between a terminal and a circuit board from increasing.